This project is a prospective investigation of the impact of emergency department (ED) crowding on patient outcomes. ED crowding is a national problem which has received much attention in the lay press as well as in the peer-reviewed medical literature. However, the extent to which crowding negatively impacts health outcomes has not been investigated. The focus of this study is the degree to which inpatient access block (i.e., the inability to free up ED beds for new patients due to delays in obtaining hospital beds for admitted patients) causes significant delay in time-sensitive ED treatments. Inpatient access block decreases the functional capacity of the ED, increasing wait times and resulting in congestion. The study is divided into two parts: (1) a prospective data collection phase where ED crowding data are collected by study personnel in a large, urban, academic ED; and (2) an explicit, structured chart review of all patients who receive parenteral (intravenous or intramuscular) antibiotics or narcotic analgesics during the course of the study. Delay in administration of parenteral narcotics is known to result in increased morbidity and mortality in patients with serious infections.